Balanced centrifugal pump.



SEPI-I H. SEBALD, OF EASTON, PENNSYLVANIA, ASSIGNOR T0 A. CAMERON STEAM PUMP W'OKS, OF NEW YORK, N. Y., A CORPORATIONOF NEW JERSEV BALANCE]] CENTRILF UGAL PUMP.

Application file July 8, 1914.

``subject of the Emperor of vustria-Hungary,

having taken out myf first naturalization papers in the United States, residing at Easton, in the county, of Northampton find State of Pennsylvania, have invented a certain' new and useful Improvement in Balanced lentrifug'al Pumps, of which the following is a specification.

This invention r'elates to centrifugal pumps, and more particularly to means for balaricing the end thrustV in single stage puinps of the double suction type. ln

'pumps of this type which have two opposite inlet openings discharglng' into a common outlet Chamber the end thrust is balanced theorctically, but not practically, due to the impsibility ofrgetting all the parts entirely symmetrical. There is usually a Considerable end thrust in one direction or the other which has to be taken up by a thrust bearing, causing friction losses.

The'object of this invention is to obviate this end thrust, and with this object in view a balancing arrang'ement has been devised, a practical embodiment of which is represented in the accompanying drawings, in which,

Figure l shows a longitudinal Vertical section through the pump on the shaft line, and Pig. 2 an end elevation of the pump cylinder.

As shown in the drawings, the pump shown Comprises a casing 1 in which' is a volute diseharge Chamber 2 and an inlet ehamher 3, the discharge Chamber 2 having opposite en'eular apertures at and 5 opening into the discharge Chamber 2. Rotating m.

,the discharge chamber 2 is the impeller 6,

which consists of a central disk 'Z secured to the shaft 8, two sets of blades 9 and 10 oni either side of the dislr 7, these blades coming together at the outer edge of the disk, and coverings ll. and 12 which are secured to the outer edge: of the hlades and having cylindrical sleeve portions 13 and 14: which Contact with the inner edges of the cylindrical operings ll and 5. Surrounding the upper side of the discharge Chamber 2 and formed integral with the casing is a by ass conduit 15 which has apertures 16 an 17 opening into the sides of the 'dischar e Chamber adiacent to the outer faces of t ie 'specification of Letters Patent.

mieniem sem. s, ile-ie.

Serial No. 849,629.

covers 11 and 12 of the impeller. This by pass Conduit and its openings 16 and 17 are of considerable size and allow a free fiow ofhfiuid from one side of the casing to the ot er.

In the operation of a pump of this type,

the unsymmetrical construction of the impeller, which is unavoidable in commercial manufacture, almost invariably causes a eonsiderably greater flow of fluid to one side of the impeller than to the other. The result is that the pressure of fiuid on one cover of the ixnpeller is Considerably greater than on the other, forcing the impeller to .one side or the other. It is impossible for this pressure to be equalied inside the discharge Chamber as there is a solid wall of Water comingl out from the impeller and striking the inner face of the discharge Chamber 2. This water wall prevents the passage of any fluid from one side of the impeller to the other. The by pass Conduit 15 allows the fluid from one side of the impeller to flow freely to the other side, thus equalizing the considerable (flifference in pressure on the outer faces of the impeller Covers and to a 'large extent eliminating the end thrust on the shaft. As it is often necessary for a.

large amount of water to pass through this conduit 15 it must be of considerable size.

lt is to be understood that while the present showing and description discloses only one specified modification of the invention, other forms and m'odifications are included in the spirit and scope of the invention, as expressed in the claims.

What l claim is:

1. In a Centrifugal pump, an impeller'casing, a double suction impeller in said casing, said impeller having covers, and a free by pass connection for lthe pumped fluid from one sideof said Casing to the other to halance pressures on the covers of said impeller. I

2. In a centrifugal pmn'p7 an impeller casing having a peripherai Outlet Chamber and opposite lateral in'ct openings, an impeller having; a central disk, and Covers itting" said laterai inlet e'oenings and projecting outv.'ar '.ly therefrom, and a free connection for the puinped fluid between the sides of said casing' to balance the lateral pressures on said Covers.

channel srving zo convey fluid to balance pressures on the xmpeler coVers. 10

In testlmony whereof, I have hereunto set my hand. w

JOSEPHH. SEBALD. Witneses:

-ELLIs NATHAN,

OTTO K. JOHANNSEN. 

